Intermittent clutch slip

[Jack4688]

I first noticed clutch slip under hard acceleration in 3rd and 4th i.e. overtaking manoeuvres back in the winter and thought 'OK, clutch is on its way out and it'll need replacing soon'. But it stopped slipping at all and only this weekend appeared again, under the same conditions. It was however much more noticeable, let's just say those overtaking manoeuvres were 'interesting'.

This week however, I have not been able to replicate it under the low stress driving conditions of plodding along to work. I even tried this morning by dropping to 3rd and full throttle at 50mph on the M62 slip road but nothing untoward happened

My question is: is this normal for initial clutch wear until it constantly slips or does it indicate something else wrong, not necessarily the clutch plates? I'm prepared to get it replaced but don't want to waste money if it is something else wrong. It is worth noting the conditions when it has slipped have been similar - late night, so possibly colder than most of my driving time and also accelerating from a 50ish mph cruise to get some speed up.

[mike74]

How's the bite point on the pedal? ie has the master cylinder ever been replaced and needs a linkage adjustment?
It does sound a bit odd though

[Jack4688]

Bite point is fine I haven't noticed any difference in 13 months ownership. Only evidence of clutch work is a hand-written note from 2005 "fit customer's own clutch..." so no confirmation of the master cylinder even being touched. Maybe I should leave it a while to see if it gets worse over time?

[SteveH]

Contamination reaching the friction plate? Any sign of fluid leaks?

[steverrquattro]

Contamination reaching the friction plate? Any sign of fluid leaks?

That's what has happened to mine. The slave cylinder has gone and dumped fluid everywhere.

[Jack4688]

But did yours slip at surprisingly long intervals? Wouldn't fluid contamination lead to a more persistent clutch slip?

[andyg plym]

I had this when main end seal was leaking, ended up on the clutch

[Jack4688]

[Jack4688]

No sign of an oil leak, oil level is pretty healthy too. Oil consumption has been noticeable though, but since I performed a service on it in October it has got much better. Regardless, the rate at which it consumed oil has never concerned me. I've had worse, and not just from my Alfa!

Should a warm, wearing, clutch perform worse than a cold one? Perhaps that is why I haven't been able to replicate it on my 15 minute drive to work and the two instances it occured were on a 150 mile journey.

[mike74]

is there free play on the clutch pedal before it really firms up? there should be slack in the pedal before it starts to do anything...

[rynaqui]

This used to happen to me, it was a result of the massive heat we have in Malta. Mine was RS2 spec with a new stock clutch. In cold weather there was no sign of slipping at all. In the heat during day time + traffic the clutch would have a much harder time.

That was my issue anyway

[Jack4688]

Hmmm it seemed alright last week when we had hot weather, though not Malta hot! There is indeed a bit of free play in the clutch before firming up, hard to say but it feels like 1/4-1/2 inch

[mike74]

that ^^^ could be your problem right there. If the clutch pedal hasn't got any slack in it, its like driving with your foot partially on the clutch ie slippage!
I had it before on a previous car which wouldn't accept anything more than half throttle. slackened clutch pedal a smidge and it was perfect
definitely worth investigating anyway...

[Jack4688]

Well that's the thing - it isn't constantly slipping. Is 1/2"ish not enough play?

[tomble]

My URS4 would occasionally slip in 6th gear and wot. there was no rhyme or reason to it though... its character i guess ha.